Python Concurrency

#!/usr/bin/env python
# -*- coding: utf-8 -*-

import threading

def fun1(n):
    print(n)

if __name__ == "__main__":
    t1 = threading.Thread(target=fun1, args=("thread 1",))
    t1.start()
    t1.join()

#!/usr/bin/env python
# -*- coding: utf-8 -*-

import threading

class MyThread(threading.Thread):
    def __init__(self, n):
        threading.Thread.__init__(self)
        self.n = n

    def run(self):
        print(self.n)

if __name__ == "__main__":
    t1 = MyThread("thread 1")
    t1.start()
    t1.join()

#!/usr/bin/env python
# -*- coding: utf-8 -*-

import multiprocessing

def fun1(n):
    print(n)

if __name__ == '__main__':
    p = multiprocessing.Process(target=fun1, args=('process 1',))
    p.start()
    p.join()

#!/usr/bin/env python
# -*- coding: utf-8 -*-

import multiprocessing

class MyProcess(multiprocessing.Process):
    def __init__(self, n):
        multiprocessing.Process.__init__(self)
        self.n = n

    def run(self):
        print(self.n)

if __name__ == "__main__":
    p = MyProcess("process 1")
    p.start()
    p.join()

#!/usr/bin/env python
# -*- coding: utf-8 -*-

from multiprocessing import Process, Value, Array

def f(n, a):
    n.value = 3.1415927
    for i in range(len(a)):
        a[i] = 100 + a[i]

if __name__ == '__main__':
    num = Value('d', 0.0)
    arr = Array('i', range(10))

    p = Process(target=f, args=(num, arr))
    p.start()
    p.join()

    print(num.value)
    print(arr[:])

#!/usr/bin/env python
# -*- coding: utf-8 -*-

import os
import time
from multiprocessing import Pool

def show(num):
    print('subproc pid=' + str(os.getpid()))
    time.sleep(1)
    print('num=' + str(num))

if __name__=="__main__":
    print('main pid=' + str(os.getpid()))
    pool = Pool(processes = 2)       # 创建进程池，最多两个进程
    for i in range(6):
        pool.apply_async(show, args=(i, ))
    pool.close()
    pool.join()                      # 等待所有子进程结束
    print('end')

#!/usr/bin/env python3
# -*- coding: utf-8 -*-

import concurrent.futures
import math

PRIMES = [
    112272535095293,
    112582705942171,
    112272535095293,
    115280095190773,
    115797848077099,
    1099726899285419]

def is_prime(n):
    if n % 2 == 0:
        return False

    sqrt_n = int(math.floor(math.sqrt(n)))
    for i in range(3, sqrt_n + 1, 2):
        if n % i == 0:
            return False
    return True

def main():
    with concurrent.futures.ProcessPoolExecutor() as executor:
        for number, prime in zip(PRIMES, executor.map(is_prime, PRIMES)):
            print('%d is prime: %s' % (number, prime))

if __name__ == '__main__':
    main()

import shutil

# We can use a with statement to ensure threads are cleaned up promptly
with ThreadPoolExecutor(max_workers=4) as executor:         # 当所有提交的任务完成后，才会退出 with 语句，不需要额外的同步操作
    executor.submit(shutil.copy, 'src1.txt', 'dest1.txt')
    executor.submit(shutil.copy, 'src2.txt', 'dest2.txt')
    executor.submit(shutil.copy, 'src3.txt', 'dest3.txt')
    executor.submit(shutil.copy, 'src4.txt', 'dest4.txt')

#!/usr/bin/env python3
# -*- coding: utf-8 -*-

import concurrent.futures
import urllib.request

URLS = ['http://www.foxnews.com/',
        'http://www.cnn.com/',
        'http://europe.wsj.com/',
        'http://www.bbc.co.uk/',
        'http://some-made-up-domain.com/']

# Retrieve a single page and report the URL and contents
def load_url(url, timeout):
    with urllib.request.urlopen(url, timeout=timeout) as conn:
        return conn.read()

# We can use a with statement to ensure threads are cleaned up promptly
with concurrent.futures.ThreadPoolExecutor(max_workers=5) as executor:
    # Start the load operations and mark each future with its URL
    future_to_url = {executor.submit(load_url, url, 60): url for url in URLS}
    for future in concurrent.futures.as_completed(future_to_url):
        url = future_to_url[future]
        try:
            data = future.result()
        except Exception as exc:
            print('%r generated an exception: %s' % (url, exc))
        else:
            print('%r page is %d bytes' % (url, len(data)))